~It’s looking like General Manager Ted Thompson was right when he decided in the offseason that the Green Bay Packers would have a quality pass rush without adding another notable outside linebacker.

But if Clay Matthews misses any upcoming games, that rush, and the Packers’ overall defense, become much more ordinary.

Matthews appears on his way to catching cornerback Charles Woodson as the team’s most important defensive player – a top pass rusher is worth more than a great player at any other defensive position, and Matthews not only rushes well but is a complete outside linebacker. His value was evident when he missed the fourth quarter (and overtime) of the Packers’ 16-13 loss to Washington on Sunday.

The Packers are saying Matthews’ strained left hamstring, which forced him out of the game for good with about two minutes left in the third quarter, isn’t as severe as in training camp, when he missed four weeks. But NFL injury information and prognoses of hamstring injuries are equally unreliable. Maybe Matthews plays this week, maybe he misses two or three games. There’s no knowing.

Regardless, other than quarterback Aaron Rodgers’ concussion, Matthews’ injury ranks as the most important on the Packers’ list of 11 players who either couldn’t play or were unable to finish the game.

In the first 43 minutes Sunday, the Packers gave up 172 yards in total offense and three points. Without Matthews in the final 25 minutes (regulation plus overtime), they gave up 201 yards and 13 points.

Was the difference all Matthews? Probably not, at least in the strictest terms. The Packers sacked quarterback Donovan McNabb twice after Matthews left.

But Matthews was having a huge game against the pass and run, and he was the Packers’ one rusher who had the speed to chase down Donovan McNabb when the quarterback broke the pocket. Taken as a whole, the game illustrates just how important Matthews is to the Packers.

Former NFL scout Michael Lombardi: “When Clay Matthews left for the Packers (in the 4th quarter), so did their ability to stop the Redskins."

Former NFL scout Michael Lombardi attended the game Sunday, and as he put it in his Monday blog on NFL.com among several quick-hit observations from around the league: “When Clay Matthews left for the Packers, so did their ability to stop the Redskins. If he cannot play next week, there has to be reason for concern.”

Going into the season, perhaps the biggest question about the Packers was their pass rush. Based on last season, it was going to be at least decent, but would it be good enough to win a championship after Thompson failed to sign or draft an outside linebacker to play opposite Matthews?

All along, Thompson argued that defensive linemen Cullen Jenkins and B.J. Raji, plus the player he selected in the second round of this year’s draft, Mike Neal, would collectively make a bigger difference than last season with pressure from the inside. He also predicted Brad Jones or an undrafted rookie would come through at the other outside linebacker.

Well, through five games, though no one has emerged as a viable outside threat to complement Matthews, the Packers’ rank second in the NFL in sacks with 21. Matthews leads the NFL with 8½ sacks, but the inside rushers have produced too.

Inside rushers don’t necessarily have to put up sack numbers to be a factor, but in the Packers’ case they are. Their trio has 7½ sacks combined in five games. That includes four by Jenkins even though he broke his hand in the opener and has been playing with a protective club since. He was a menace Sunday even though he didn’t have a sack, and he might have dropped McNabb two or three times if he’d been able to grab with both hands.

The biggest jump from last season is with Raji, who has 2½ sacks. Coming off a relatively middling training camp, he’s starting to look like the player Thompson projected when he selected him at No. 9 overall in the 2009 draft.

And Neal, though raw, has one sack in spot duty in his two games since coming back from an abdominal strain. He’s had fairly consistent push as an inside rusher, which helps shrink a quarterback’s room to move in the pocket.

Combined with defensive coordinator Dom Capers’ varied zone-blitz calls – Brady Poppinga went unblocked on his overtime sack of McNabb – and the Packers have had one of the best pass rushes in the NFL.

But Matthews was the linchpin, and taking him out changes the dynamic of how he and the other rushers help each other.

If Matthews can’t play this week, the Packers won’t have an outside rusher who commands double teams. Miami will assume it can block Jones, Frank Zombo and Poppinga with tackles Jake Long and Vernon Carey. That in turn will leave more options for doubling the interior rushers.

Capers still will have his zone blitzes and the ability to move around his linebackers to send them from alternate angles, which might create confusion pressures and a sack or two. But there’s no beating having players with superior ability who either make the plays or command so much attention they help others make them.